In process control systems, such as distributed or scalable process control systems commonly found in chemical, petroleum, power generation, or other industrial processes, it is often necessary to reduce the pressure of a fluid. However, pressure reduction typically leads to increased levels of unwanted noise and/or vibration, as discussed in the Background section of U.S. Pat. No. 6,935,370 (“the '370 Patent”). Thus, process control systems often employ flow restriction devices that aim to reduce fluid pressure in a manner that does not lead to increased levels of noise and/or vibration. Such flow restriction devices may include, for example, flow control valves, fluid regulators, valve cages, diffusers, silencers.
The '370 Patent illustrates several different examples of fluid pressure restriction devices each taking the form of a plurality of stacked disks that, when employed in a fluid flow control valve, reduce the pressure of a fluid flowing therethrough. One example, illustrated in FIG. 5 of the '370 Patent, features a plurality of stacked annular disks 100 rotated relative to one another to create flow paths 62 that each provide multi-stage pressure reduction. Each disk 60 of the stack 100 has a laser cut profile defining a horizontal, spiral flow path 62 that extends from an inlet section 68, through an intermediate section 70 formed of a series of flat leg portions and including restrictions 74, 76, and to an outlet section 72 having a larger cross-sectional area than the inlet section 68. Another example, illustrated in FIG. 8 of the '370 Patent, features an annular disk 130 that defines intersecting fluid flow paths 136, 138 so that fluid flowing therein collides, thereby releasing energy and reducing fluid pressure.